Draft gears



May 28, 1957 Filed June 11, 1954 H. W. MULCAHY DRAFT GEARS 4 Sheets-Sheet 1 Inveglor. 519 Z fl 9 May 28, 1957 H. w. MULCAHY 2,793,765

DRAFT GEARS I 4 Sheets-Sheet 2 Filed June 11, 1954 Jaw WWII/Z0012 May 28, 1957 1H. w. MULCAHY 2,793,765

' DRAFT GEARS Filed June 11, 1954 4 Sheets-Sheet 5 In-V'en%r:

United States Patent DRAFT GEARS Harry W. Mulcahy, Chicago, 111., assignor to W. H. Miner, Inc., Chicago, Ill., a corporation of Delaware Application June 11, 1954, Serial No. 436,018

Claims. (Cl. 213-23) This invention relates to passenger type friction draft gear for railway draft riggings. 7

It is a main object of the invention to provide a pas senger type friction draft gear which is a self-contained unitary structure arranged tohave initial free spring travel followed by friction travel when impacts are imposed upon the gear.

Another object of the invention is to provide a draft gear having a metallic casing formed in two sections which are telescoped together and held against the tension of resilient means in the casing by interengaging means on the sections.

Another object of the invention is to provide a draft gear casing consisting of two sections which are assembled together first by translatory movement and then by rotary movement, thereby to move lugs on the inner section through grooves in the outer section into registration with branches of the grooves in which the lugs are i moved by impacts telescoping the sections against the yielding resistance of a resilient means contained in the casing. Y

Another object of the invention is to provide a draft gear casing having two sections telescoped together and held by lugs positioned in grooves and in which the edges of the casing wall defining the grooves and the lugs are shaped in such manner as to insure that the casing sections will be movably secured together and maintained in proper alignment.

Another object of the invention is to provide a draft gear having a casing composed of two sections telescoped together and containing a resilient column with one of the sections containing outwardly projecting flanges normally spaced from the free end of the other section in which the first section is telescoped so that impacts imposed upon the gear will move the sections relative to each other and against the yielding resistance of the resilient column until the flanges engage the-end of the other casing section.

Further objects of the invention not specifically mentioned here will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which:

Figure 1 is Side elevational view of the draft gear completely assembled;

Figure 2 is a top plan view of the gear;

Figure 3 is a side elevational view of the draft gear;

Figure 4 is a front elevational view of the rear casing section;

Figure 5 is a side elevational view of the front section of the casing;

Figure 6 is a rear elevational view of the front section of the casing;

Figure 7 is a cross sectional view taken substantially along the line 77 of Figure 4, looking in the direction of the arrows;

Figure 8 is a cross sectional view taken along the line 8-8 of Figure 3, looking in the direction of the arrows;

Figure 9 is a cross sectional view taken along the line 9-9 of Figure 8, looking in the direction of the arrows; and

Figure 10 is a cross sectional view taken along the line 1010 of Figure 2, looking in the direction of the arrows.

As will be seen in the drawings, my improved passenger type friction draft gear consists broadly of a casing having a front section A and a rear section B, into which a cylindrical portion of the upper section is telescoped. Contained within the casing is a friction device consisting of shoes C and a wedge block D which projects from the open end of casing section A. Also contained within the casing is a resilient column E which, in the example shown, consists of a pair of concentrically disposed coil springs.

The front section A of the casing contains a generally cylindrical portion 10 adapted to fit in a cylindrical portion 11 in the rear section B of the casing. Section A also contains a front portion 12 containing an opening which is generally hexagonal and in which friction shoes C are disposed. The hexagonal walls of the front portion 12 of the casing are tapered slightly, as is the custom in friction gears of this type. The wedge block D contains tapered walls 13 which register with corresponding walls in the shoes C, so that as the wedge block is forced inwardly of the casing the shoes will be forced outwardly into tighter frictional engagement with the wall 12. Lugs 14 on the casing section A are engaged by ears 15 on the wedge D to hold the friction elements in the casing section.

As will be seen best in Figure 6, the front portion 12 of the section A is generally circular in outer configuration and is of greater diameter than the cylindrical portion 10. Thus, a shoulder 12a is formed at the junction of portions 10 and 12, which shoulder extends radially outwardly from the portion 10. This shoulder engages the end of section B as the sections are telescoped, thus limiting the free spring travel of the gear.

The rear section B of the casing is closed at one end by a wall 16 which contains a central perforation 17, through which the shank of the hook couplers used in foreign countries may be extended if desired. Section B also contains outwardly extending flanges 18 reinforced by rib 19 and adapted to bear against lugs on the sills of a railway vehicle to position the gear with respect thereto.

As will'be seen best in Figures 5 and 6, the cylindrical portion 10 of the front section A of the casing contains lugs 20 which in the embodiment shown by way of example are four in number and are inclined with respect to the axis of the section and the lower end thereof in juxtaposition to which these lugs are located. The wall 11 of the rear section B of the casing contains grooves 21, likewise four in number, and with which the lugs 20 are adapted to be registered. I

As will be seen best in Figure 7, each groove 21 contains a branch 22 that opens into the front end of the section B, a second branch 23 which extends around the wall of the SectiOn from the rear end of the branch 22 and at an acute angle thereto. Each groove contains a third branch 24 which is parallel to the firstbranch 22 and extends to the rear wall 16 of the section.

The resilient column B, which in the example shown consists of concentrically disposed coiled springs, fits within the casing sections and bears against the end wall 16. l V

In assembling the gear, the rear casing section B is placed in upright position and section A registered therewith, with the lugs 20 disposed in the branches 22 of the grooves 21, the section A then being lowered until the lugs engage the bottoms of the branches 22 of the grooves. Section A is then rotated with respect to section B to move the lugs upwardly through branch 23 of the groove into registration with the upper end of the branch 24 thereof. Temporary means, such as blocks of wood, are inserted between the upper end of the section B and the flange on section A to hold the parts in this position.

The resilient column E, consisting of concentric coiled springs, are then placed Within the casing, after which shoes C are placed therein and forced down against the yielding resistance of the column B. The wedge block D is then inserted and rotated to bring the ears into registration with the lugs 14, thereby to lock the assembly together. The temporary blocks may then be removed.

The thus assembled gear is installed in the draft rigging within the yoke and pocket, with the flanges 18' engaging the usual lugs defining one end of that pocket. A follower, notshown, is placed against the projecting end of the wedge block D and lugs on the sills defining the other end of the pocket.

When the gear is stressed by impacts in buff or in draft, sections A and B of the casing telescope together against the yielding resistance of the resilient column until the shoulders 12a of section A engage the ends of the wall 11 of section B. This free spring travel of the gear constitutes the main portion of the travel thereof. If the impact is greater than required to move the flange against the end of the housing, further movement forces the wedge inwardly of the casing thereby to cause the friction shoes to move with respect to the casing and absorb the force of the impact. This latter movement, which also further compresses the resilient column E, is a relatively short movement compared to the initial free spring movement of the gear.

During movement of the housing sections inwardly and outwardly with respect to each other, lugs 20 travel in the branch 24 of the grooves engaging the lateral walls thereof to maintain the housing sections in proper alignment. When the lugs 20 engage the front ends of the branches 24 of the grooves, the inclined surfaces of the lugs and Walls of the groove are engaged to lock section A with respect to section B. It will be noted that there is an inclined section 25 in the walls defining the groove, and a corresponding inclined end 26 on the lugs 20, which inclined surfaces insure that the lugs 20 will be properly registered in grooves 24 at all times.

Having thus complied with the statutes, and shown and described a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What is claimed is:

1. A draft gear for railway draft rigging, comprising a casing consisting of a cuplike rear section and a front section open at both ends and telescoped into said rear section; pressure transmitting means disposed within said front section of said casing and projecting outwardly from the front end thereof; resilient means within the rear section of the casing extending into the front section thereof and pressing against said pressure transmitting means; inturned flanges on said front section engaging said pressure transmitting means to hold the same in the casing against the pressure of said resilient means,.said rear section of said casing containing grooves opening inwardly of the walls thereof; and lugs on the telescoped portion of said front section projecting radially therefrom into said grooves and engaging the walls of the grooves to hold the gear together by holding said front section against the pressure of said resilient means transmitted to it through said pressure transmitting means.

2. A draft gear as specified in claim 1, in which the grooves in the rear section of the casing are generally N-shaped and disposed with one branch opening into the open end of the section and another branch parallel to the first extends towards the closed end of the section and in which a connecting branch of the groove slopes towards the latter branch so that engagement of the lugs with the connecting portion tends to rotate the front section of the casing towards locked position.

3. A draft gear for railway draft rigging, comprising a metallic casing consisting of two sections telescoped together; a friction means positioned in one of said sections and projecting therefrom; resilient means disposed in the casing and engaging said friction means, and interengaging means on said sections for holding the gear together as a unit, said interengaging means comprising grooves in one section and lugs on the other section projecting into said grooves and engaging the edges thereof to prevent relative rotation of the sections while permitting the sections to be telescoped together against the yielding resistance of said resilient means by impacts imposed upon the gear.

4. In a draft gear for railway draft rigging, a metallic casing consisting of two sections telescoped together; a friction means positioned in one of said sections and projecting therefrom; shoulder means on said section projecting radially therefrom and normally spaced from the end of the other section into which the first mentioned section is telescoped; resilient means disposed in the casing and engaging said friction means; and interengaging means on said sections for holding the gear together as a unit, said interengaging means permitting impacts on the gear first to telescope the sections and compress said resilient means until said shoulder means engages the end of said other section and then to move the friction means into the section in which it is positioned and further compress said resilient means.

5. In a draft gear for railway draft rigging, ametallic casing comprising two sections each having a portion of cylindrical cross section, which portions are telescoped one within the other; groove means in the first of said sections having first branches extending axially inwardly from the open end of the section, second branches inclined with respect to the first branch and extending a short distance around the section, and third branches parallel to the first and extending axially inwardly from the second branches; a wall closing one end of said sectionand defining ends to said third branches; lug means projecting radially outwardly from one end of the cylindrical portion of the second section and having opposed faces disposed at an angle to the axis of the section corresponding to the inclination of said second branches, said lug means. fitting in and moving through said grooves as the sections are assembled together first with translatory movement and then with rotary movement; resilient means within saidcasing urging said lug means against the ends of the third branches at the junctions of the second and third branches, said lug means moving in said third branches as impacts on the casing telescope said sections against the yielding resistance of said resilient means.

References Cited in' the file of this patent UNITED STATES PATENTS 1,014,108 Wild .a Jan. 9, 1912 1,523,928 Berney et al. Jan. 20, 1925 2,354,826 Olander Aug. 1, 1944 2,434,943 Marsh Ian. 27, 1948 2,532,013 Dath Nov. 28, 1950 

